1. Field of the Invention
This invention relates to seatbelt systems which restrain and protect passengers during vehicular emergencies and more specifically to seatbelt systems in which one end of the passenger restraining seatbelt is fastened to the passenger seat.
2. Prior Art
Generally, seatbelt systems are designed such that one end of the passenger restraining seatbelt is power retracted on a retractor fastened to the vehicle so that a specified tension is placed on an intermediate portion of the seatbelt. As a result, the seatbelt is caused to adhere closely to passenger. Furthermore, when the seatbelt is not in use, it is power retracted and stored inside the retractor. In addition, during a vehicular emergency, the extension of the seatbelt is abruptly stopped by an inertial locking mechanism provided inside the retractor. As a result, tension on the seatbelt generated by the movement of the passenger in the direction of impact is transmitted to the vehicle via the retractor and the passenger is securely restrained so that his safety is insured.
In case where the retractor is fastened to the vehicle, however, since the position in which the passenger rides in the vehicle changes according to the adjustment of the position of the passenger relative to the seatbelt system changes, the performance of the seatbelt system varies according to the adjustment of the position of the passenger seat. As a result, it becomes necessary to adjust position in which the seatbelt is fastened. Recently, passive seatbelt systems have been proposed which are able to automatically fasten the seatbelt around the passenger after the passenger has seated himself in the passenger seat. In cases where such systems are used, it is necessary to fasten a retractor to the passenger seat so that the passenger is constantly kept in an appropriate restrained condition. However, in cases where a retractor is fastened to the rear of the passenger seat, the retractor interferes with the leg room of the passengers seated in the rear seat. Furthermore, a substantial resistance is imparted to the intermediate portion of the seatbelt which extends under the seats so that the retracting force of the retractor is reduced.